On Fri, May 12, 2017 at 01:15:47PM -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (VMware)" <rost...@goodmis.org>
>
> jump_label_lock() is taken under get_online_cpus(). Make sure that kprobes
> follows suit.
>
> Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
The remaining three (3/5 through 5/5) look straightforward. #4 appears
to be the one needing the recursive get_online_cpus().
Thanx, Paul
> ---
> kernel/kprobes.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index d733479a10ee..57cf73aef488 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -1294,13 +1294,13 @@ static int register_aggr_kprobe(struct kprobe
> *orig_p, struct kprobe *p)
> int ret = 0;
> struct kprobe *ap = orig_p;
>
> - /* For preparing optimization, jump_label_text_reserved() is called */
> - jump_label_lock();
> /*
> * Get online CPUs to avoid text_mutex deadlock.with stop machine,
> * which is invoked by unoptimize_kprobe() in add_new_kprobe()
> */
> get_online_cpus();
> + /* For preparing optimization, jump_label_text_reserved() is called */
> + jump_label_lock();
> mutex_lock(&text_mutex);
>
> if (!kprobe_aggrprobe(orig_p)) {
> @@ -1348,8 +1348,8 @@ static int register_aggr_kprobe(struct kprobe *orig_p,
> struct kprobe *p)
>
> out:
> mutex_unlock(&text_mutex);
> - put_online_cpus();
> jump_label_unlock();
> + put_online_cpus();
>
> if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) {
> ap->flags &= ~KPROBE_FLAG_DISABLED;
> --
> 2.10.2
>
>
